Whereas the vast majority of Bluetooth wireless accessory reviews we do are straightforward, the last month has been unusual in that we've received a number of different items that we were told were finished, yet in our testing turned out to be a little incomplete. For instance, Contour Design's stunningly thin Metal Bluetooth Headset turned out to have some charging issues, and now iVoice's Diamond-X Bluetooth Headset ($99) has been going through firmware changes. The first two versions we tried did everything right except for Diamond-X's signature feature: this was to be the first Bluetooth earpiece capable of telling you the name of your incoming caller, using a digitized voice.

To start this review out with good news, then, we’ll tell you that the “final” version of Diamond-X we’ve tested works exactly as promised. Pair it with your iPhone or iPhone 3G, put it in your ear, and wait for a call. Without any need for a lengthy setup or synchronization process, if the caller’s in your iPhone’s directory, you’ll hear a brief ringing chime followed by his or her name pronounced decently, otherwise, you’ll hear a telephone number. In any case, your iPhone’s ringtone will be audible from the iPhone itself. The same voice technology enables Diamond-X to tell you its own Bluetooth pin code for pairing, rather than forcing you to guess or consult a manual, and lets you know that it’s “ready” when powered up, or “powering down” when turned off. These are handy if not exactly essential features for a Bluetooth headset to have.

There are other things to like about Diamond-X, as well. Like many of the newer, post-Jawbone Bluetooth headsets we’ve seen, it features twin microphones and noise-cancelling functionality. Unlike the current four-hour version of Jawbone, it promises 5.5 hours of talk time or 200 hours of standby time on a single battery charge, and iVoice packs it with nice charging goodies: a smart, flexible USB cable—probably our favorite accessory ever included with a Bluetooth headset, due to its convenience factor—as well as a wall charger, a car charger, and comfort pieces. Six total rubber eartips are included for the headset, which will stay mounted in some ears without assistance, and two adjustable, detachable ear stems are also packed in for those who need additional ear stability.

The earpiece itself comes in four colors—red, black, brushed metallic, and chrome—each with an illuminating multifunction and power button that glows behind a silver diamond-like facade. We’ve seen all but the black one in person, and like the way that all of them look, though we’d lean towards the dark chrome or glossy red ones over the slightly faux brushed metallic. The shape, size, and weight are all inoffensive, and though there’s no doubt that none of the Diamond-X models is as simple as Apple’s or Contour Design’s Bluetooth earpieces, we wouldn’t hesitate to wear these, either. Our only issue in testing was with the ear hooks: despite a nice attempt at making the hooks repositionable, we did better keeping the earpieces in an ear unassisted than we did with the hooks. iVoice needs to keep working on these.

Sonically, Diamond-X did pretty well in our testing. Callers told us that its sound was slightly more bass-skewed than the Jawbone, with a little less treble emphasis, which made our voices sound a little more natural and a hint less intelligible—still very good. When background noise was turned up to a distracting level, callers told us that the Jawbone did a “much better” job of eliminating the noise almost entirely, but Diamond-X’s dual-microphone array substantially reduced it, leaving voices easy to understand.

The same callers gave Diamond-X a slight edge offer Griffin’s recent SmartTalk, saying that while SmartTalk presented our voices with slightly more natural sound, this difference was modest, and Diamond-X sounded better overall due to its absence of SmartTalk’s odd fade-in behavior, and less of a staticy sound when eliminating background noise. By comparison with the iPhone’s own speaker and mic in handset mode, Diamond-X’s audio was described as sounding more compressed, presenting voices with less “life,” though not offensively so. The Diamond-X design eliminated more background noise, as well.

One other interesting feature iVoice has included in Diamond-X is an automatic volume control: the device ups the volume level of the speaker in your ear to compensate for ambient noise. While the feature works, the changes are gentle, and you may find that you want to boost the volume on your own; since Diamond-X doesn’t have integrated volume buttons, this is handled with the volume controls on your iPhone, and works just fine.

Our single biggest concern about Diamond-X isn’t its overall sound performance, the quality of the parts in its package, or its pricing, which collectively place it in direct competition with comparable headsets from Aliph, Apple, and Griffin, frankly offering plenty of bang for the buck relative to these earlier products. It’s solely the issue of whether users will wind up with the right firmware installed on their headsets. iVoice says that they definitely will: after a shipping delay that saw Diamond-X miss its original January release date, we’ve been told that only units with the proper firmware “will be sent to retailers and will be able to be purchased by consumers.”

If iVoice lives up to its word, which we believe that it will, users will receive Diamond-X units that do exactly what they’re promised to do in a surprisingly efficient and generally quite impressive manner; if not, the absence of the promised and noteworthy caller announcement feature will bother many users as much as it initially bothered us. Just in case there’s a problem, here’s our advice: should this headset’s features and looks interest you, we’d recommend choosing a vendor with a no-questions-asked return policy just in case you have an issue with firmware or fit. If your Diamond-X unit is as good as the “final” one we tested, we suspect that you’ll be as impressed as we were, and find the caller identification feature to be a compelling new addition to the Bluetooth headset category. On the other hand, if you have any problems, e-mail us and let us know so we can update this review accordingly.

Editors' Note: iLounge only reviews products in "final" form, but many companies now change their offerings - sometimes several times - after our reviews have been published.
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